Elevated rates of attention deficit and overactivity have been noted previously in samples of institution-reared children. This study examined the hypothesis that inattention/overactivity(I/O) might constitute a specific deprivation syndrome. One hundred and sixty five children adopted at varying ages (e.g., 0-42 months of age) into the UK following severe early deprivation were compared with 52 within-UK adoptees who did not suffer deprivation. The children were rated by teachers and parents on levels of I/O, conduct difficulties, and emotional difficulties using the Revised Rutter Scales. Data were collected at age 6 for the entire sample and at age 4 for the UK adoptees and for the subsample of Romanian children who entered the UK before the age of 2 years. Mean level analyses suggested a significant effect of duration of deprivation on I/O, but not on conduct or emotional difficulties. The effects of duration of deprivation were specific to I/O and were not accounted for by low birth weight, malnutrition, or cognitive impairment. Levels of I/O correlated with attachment disturbances. Furthermore, the effects of duration of deprivation on I/O did not attenuate over time. We conclude that I/O may well constitute an institutional deprivation syndrome, but that the type of attention deficit and overactivity exhibited by these children may present a different clinical picture from that of "ordinary" varieties of attention deficit disorder or hyperkinetic syndrome.